Millbury Solar
Worcester County, Massachusetts · EIA plant ID 58280 · Operator: First Wind O&M, LLC
Nameplate3MWSummer 3 MW
Generators1in service
Net generation5GWh12 mo to Dec 2025
Capacity factor18%solar units, summer MW
Heat rate—thermal plants only
First online2014
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), solar units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Heat rate applies to fuel-burning (thermal) units only.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2014 | 3.7 | 18.7% | — |
| 2015 | 4.7 | 17.7% | — |
| 2016 | 4.8 | 18.3% | — |
| 2017 | 4.4 | 16.6% | — |
| 2018 | 4.3 | 16.4% | — |
| 2019 | 4.9 | 18.6% | — |
| 2020 | 3.9 | 14.8% | — |
| 2021 | 4.1 | 15.5% | — |
| 2022 | 5 | 18.9% | — |
| 2023 | 4.6 | 17.3% | — |
| 2024 | 4.2 | 16.1% | — |
| 2025 | 4.7 | 17.9% | — |
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| 1 | Solar Photovoltaic | PV | 3 | 3 | Apr 2014 | Operating | — | coming soon |
Owner / operator
Operator: First Wind O&M, LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| First Wind O&M, LLC | 100.0% | 3 MW |
Nearby plants
Within 80 km.
| Syncarpha Millbury Hybrid (CSG) | 9 MW | 1.2 km |
| Oxford | 3 MW | 5.3 km |
| Barrett PV | 12 MW | 5.7 km |
| Worcester Landfill | 7 MW | 6 km |
| 3Colton | 3 MW | 6.5 km |
| Wheelabrator Millbury Facility | 48 MW | 6.7 km |